Velvet worm slime in material design

Velvet worms live in the humid forests of the southern hemisphere. When hunting, they generate a sticky slime to trap and incapacitate prey. A research team involving McGill University and Nanyang Technological University (in Singapore) has made a discovery about this slime that could revolutionize sustainable material design. Their study outlines how a naturally occurring protein structure within the slime, conserved across species from Australia, Singapore and Barbados over nearly 400 million years of evolution, enables transformation from liquid to fibre and back again. It’s a discovery that could inspire next-generation recyclable bioplastics.

“Nature has already figured out a way to make materials that are both strong and recyclable,” said Matthew Harrington, a chemistry professor at McGill and a Canada Research Chair in green chemistry, who led the study. “By decoding the molecular structure of velvet worm slime, we’re now one step closer to replicating that efficiency for the materials we use every day.”

When ejected, the velvet worm’s slime rapidly hardens into fibres as strong as nylon. However, the slime will also dissolve in water and can be reconstituted into new fibres. Until now, the molecular mechanism behind this reversibility was a mystery.

Using protein sequencing and AI-driven structure prediction (AlphaFold, the 2024 Nobel Prize–winning tool), Harrington’s team identified previously unknown proteins in the slime. These proteins function similarly to cell receptors in the human immune system. The researchers believe the receptor proteins link large structural proteins during fibre formation. By comparing 2 subgroups of velvet worms that were separated nearly 380 million years ago, the researchers demonstrated the evolutionary significance and functional relevance of this protein.

Traditional plastics and synthetic fibres are typically made using petroleum-based precursors.The manufacturing and recycling processes are energy-intensive, often involving heat or chemical treatments. However, the velvet worm uses simple mechanical forces—pulling and stretching—to generate strong, durable fibres from biorenewable precursors. These fibres can later be dissolved and reused without creating harmful byproducts.

“Obviously, a plastic bottle that dissolves in water would have limited use, but by adjusting the chemistry of this binding mechanism, we can get around this issue,” said Harrington.

The team’s next challenge will be to experimentally verify the binding interactions and explore whether the functionality can be adapted for engineered materials.

This article was adapted and published with permission from McGill University.

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